This invention relates to television techniques and, more particularly, to an improved television system and method that effectively increases the sensitivity of a television camera.
Television cameras generally require relatively high light levels for proper operation. Under studio conditions, this is typically not a problem. Outside the studio, however, such as in electronic news gathering applications, the amount of light that is available may be below the level necessary for good video quality. If natural or artificial light is insufficiently available, it may be necessary to use a wide camera lens aperture in order to capture the light necessary for a reasonable signal-to-noise level in the resultant video signal. Even the widest lens opening may be insufficient, though. Also, as is well known, certain disadvantages, such as restricted depth of field, will be a consequence of employing an unduly wide lens aperture.
It is among the objects of the present invention to provide a video system which enhances the effectiveness of the light sensed by a television camera. At very low light levels, an objective is to generate a video signal having improved signal-to-noise ratio, thereby allowing the generation of picture information when conditions would have normally prevented attainment of a picture. Also, in situations where the light level would have been sufficient to obtain a picture using existing techniques, it is an object of the invention to permit operation with a smaller camera lens aperture so as to gain the attendant advantages of such operation.